Bone Marrow Aspirate Concentrates for Knee OA

Bone marrow aspirate concentrate (BMAC) has emerged as a safe therapeutic orthobiological option to treat symptomatic knee osteoarthritis (OA). Physicians are attracted to use BMAC for knee OA treatments because of the presence of MSCs, as these specialized cells have self-renew and multidirectional-differentiation potentials. Furthermore, the heterogenous composition of BMAC has demonstrated to exert immune-modulatory functions, regulate inflammation, facilitate angiogenesis, and ultimately improve tissue repair, with painkilling effects. BMAC can be extracted from multiple anatomical sites. However, the posterior superior iliac spine (PSIS) is the most cited location for bone marrow aspirate (BMA) harvesting since most MSCs have been related to this particular harvesting site. Autologously prepared BMAC, prepared at point-of-care (POC), is a concentrated multicellular viable tissue. Following two-step BMA centrifugation procedures, gravitational density separation concentrates and organizes bone marrow cells in a buffy coat stratum. Based on the individual densities, BMAC comprises of mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), stem cell progenitor cells, platelets, leukocytes, and some red blood cells. Pre-procedural preparations, including the appropriate imaging options, patient positioning, the use of local anesthetics, the superolateral injection approach is preferred for intra-articular knee injections. Systematic reviews indicate significant patient outcomes regarding pain reduction and functional improvement.